Conventionally, with all season pneumatic tires that are used throughout the year, both steering stability on dry road surfaces (dry performance) and traveling performance on icy and snowy road surfaces (snow performance) are required. For example, in Japanese Unexamined Patent Application Publication No. 2010-168006A, dry performance and snow performance are both provided by making the groove area ratio of lug grooves and sipes disposed in five land portions partitioned and formed by four circumferential main grooves (one center land portion, two intermediate land portions, and two shoulder land portions) in the intermediate land portions greater than that in the center land portion and the shoulder land portions.
On the other hand, it is required that the noise generated by pneumatic tires fitted to a vehicle when the vehicle passes by (pass-by noise) is reduced, to improve the noise performance. It is known that one method of improving the noise performance is, for example, to reduce the groove area ratio of the tread portion. However, reducing the groove area ratio of the tread surface has the problem that the snow performance is degraded. Also, if the overall groove area ratio on the tread surface is reduced in Japanese Unexamined Patent Application Publication No. 2010-168006A while maintaining the magnitude relationship of the groove area ratios, the good balance of the tread pattern is lost, so dry performance, snow performance, and noise performance cannot be achieved at the same time. Therefore there is a demand for further improvement of these three performances to a high level.